Substrate processing apparatus and substrate processing method

ABSTRACT

A substrate processing apparatus for cleaning and drying a substrate under processing, including supplying a cleaning liquid onto the substrate under processing to form a cleaning liquid layer, supplying a gas onto the substrate under processing to partially remove the cleaning liquid layer and thus generate a first dry region on the substrate under processing, expanding the first dry region to generate a second dry region by controlling the movement speed of the boundary between the cleaning liquid layer and the first dry region to be less than or equal to a predetermined speed, and further expanding the second dry region to generate a third dry region.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2021-154588, filed on Sep. 22, 2021, theentire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

Embodiments relate to a substrate processing apparatus and a substrateprocessing method.

Description of the Related Art

A substrate processing apparatus and a substrate processing method forcleaning and drying a substrate under processing are known.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of a substrate processingapparatus of a first embodiment;

FIG. 2 is a plan view of the substrate processing apparatus of the firstembodiment;

FIG. 3 is a view for illustrating a substrate processing method thatuses the substrate processing apparatus illustrated in FIG. 1 ;

FIG. 4 is a chart for illustrating a substrate processing method thatuses the substrate processing apparatus illustrated in FIG. 1 ;

FIG. 5 is a view for illustrating a substrate processing method thatuses the substrate processing apparatus illustrated in FIG. 1 ;

FIG. 6 is a view for illustrating a nozzle holding portion in FIG. 1 ;

FIG. 7A is a view for illustrating a substrate processing method thatuses the substrate processing apparatus illustrated in FIG. 1 ;

FIG. 7B is a view for illustrating a substrate processing method thatuses the substrate processing apparatus illustrated in FIG. 1 ;

FIG. 7C is a view for illustrating a substrate processing method thatuses the substrate processing apparatus illustrated in FIG. 1 ;

FIG. 7D is a view for illustrating a substrate processing method thatuses the substrate processing apparatus illustrated in FIG. 1 ;

FIG. 7E is a view for illustrating a substrate processing method thatuses the substrate processing apparatus illustrated in FIG. 1 ;

FIG. 8 is a view for illustrating a first modified example of the nozzleholding portion in FIG. 1 ;

FIG. 9A is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 8 ;

FIG. 9B is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 8 ;

FIG. 9C is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 8 ;

FIG. 9D is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 8 ;

FIG. 9E is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 8 ;

FIG. 10 is a view for illustrating a second modified example of thenozzle holding portion in FIG. 1 ;

FIG. 11A is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 10 ;

FIG. 11B is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 10 ;

FIG. 11C is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 10 ;

FIG. 11D is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 10 ;

FIG. 11E is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 10 ;

FIG. 12 is a view for illustrating a third modified example of thenozzle holding portion in FIG. 1 ;

FIG. 13A is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 12 ;

FIG. 13B is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 12 ;

FIG. 13C is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 12 ;

FIG. 13D is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 12 ;

FIG. 13E is a view for illustrating a substrate processing method thatuses the nozzle holding portion illustrated in FIG. 12 ;

FIG. 14A is a view for illustrating a substrate processing methodaccording to a second embodiment;

FIG. 14B is a view for illustrating the substrate processing methodaccording to the second embodiment;

FIG. 14C is a view for illustrating the substrate processing methodaccording to the second embodiment; and

FIG. 14D is a view for illustrating the substrate processing methodaccording to the second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present embodiment will be described with reference tothe accompanying drawings. For easy understanding of the description,components that are the same throughout the drawings are denoted by thesame reference signs as much as possible, and repeated description willbe omitted.

First Embodiment

A substrate processing apparatus 1 of a first embodiment will bedescribed with reference to FIGS. 1 and 2 . The substrate processingapparatus 1 includes a spin chuck 2 and a cup body 3. The spin chuck 2is a substrate holding portion for holding a substrate S in thehorizontal posture by suctioning and attracting the central portion onthe rear face side of the substrate S. For the substrate S, a quartzsubstrate, such as for a photomask or a template, is contemplated, forexample. Alternatively, the substrate S may be a semiconductor wafer,such as a silicon substrate. An example in which the substrate S of FIG.1 is a photomask will be described. The spin chuck 2 is connected to adrive mechanism 22 including a rotation mechanism via a rotating shaft21. The spin chuck 2 is configured to be movable up and down whileholding the substrate S. In FIG. 1 , the substrate S is held such thatthe center of the substrate S is positioned above the rotating shaft 21of the spin chuck 2.

The cup body 3, which is open on its upper side, is provided so as tosurround the substrate S placed on the spin chuck 2. The cup body 3includes an outer cup 31, an inner cup 32, an elevating/lowering portion33, a circular plate 34, and a liquid receiving portion 35. The outercup 31 has a quadrangular upper side and a cylindrical lower side, forexample. The inner cup 32 has a tubular shape with its upper sideinclined inward, for example. The outer cup 31 is moved up and down bythe elevating/lowering portion 33 connected to the lower end portion ofthe outer cup 31. The inner cup 32 is configured to be movable up anddown by being pushed up by a step portion (not illustrated) formed onthe inner peripheral face on the lower end side of the outer cup 31.

The circular plate 34 is provided below the spin chuck 2. The liquidreceiving portion 35 is provided around the entire circumference of theouter side of the circular plate 34. The liquid receiving portion 35 hasa recessed cross-section. The liquid receiving portion 35 stores adeveloping solution, or a cleaning liquid spilled from or shaken offfrom the substrate S. The bottom face of the liquid receiving portion 35has a drain discharge port 36 formed therein. The developing solution orthe cleaning liquid stored in the liquid receiving portion 35 isdischarged to the outside of the apparatus through the drain dischargeport 36.

A ring member 37 is provided on the outer side of the circular plate 34.The ring member 37 is a member with a chevron-shaped cross-section. Thering member 37 is configured to be able to hold the inner cup 32 on itsinclined outer face. Though not illustrated, 3 elevating/lowering pins,which are substrate support pins, are provided penetrating the circularplate 34, for example. The substrate S is configured to be delivered tothe spin chuck 2 with the cooperative action of the elevating/loweringpins and a substrate transfer means (not illustrated).

The substrate processing apparatus 1 includes a developing solutionnozzle 23, a gas nozzle 4, a cleaning liquid nozzle 5, and a monitoringmechanism 6. The developing solution nozzle 23 includes a belt-likedischarge port 23 a (see FIG. 2 ) extending in the direction of thediameter of the substrate S held by the spin chuck 2. The developingsolution nozzle 23 is connected to a developing solution supply system25 via a developing solution supply channel 24, for example, a pipe. Thedeveloping solution supply system 25 includes a source of supply of adeveloping solution, a supply control device, and the like.

The developing solution nozzle 23 is supported by one end side of anozzle arm 26 that is a support member. The other end side of the nozzlearm 26 is connected to a movable base 27 including an elevating/loweringmechanism (not illustrated). The movable base 27 is configured to bemovable in the horizontal direction along a guide member 28 by means ofa drive source (not illustrated) forming a movement mechanism. A nozzlestandby portion 29 is a standby portion for the developing solutionnozzle 23. In the nozzle standby portion 29, the tip end of thedeveloping solution nozzle 23 is cleaned, for example.

The gas nozzle 4 is connected to a gas supply system 43 via a pipe 42.The gas supply system 43 includes a source of supply of a N₂ (nitrogen)gas, which is an inert gas, a supply control device, and the like. Thegas nozzle 4 is provided on a nozzle holding portion 41, for example.

The cleaning liquid nozzle 5, which is a liquid nozzle, is connected toa cleaning liquid supply system 53 via a pipe 51. The cleaning liquidsupply system 53 includes a source of supply of a cleaning liquid, asupply control device, and the like. The supply control device includesa pump and a valve capable of controlling the discharge flow rate, forexample. The cleaning liquid nozzle 5 is provided on the nozzle holdingportion 41, for example.

The nozzle holding portion 41 is provided at the tip end of a nozzle arm44. The nozzle arm 44 is connected to a movable base 45 including anelevating/lowering mechanism. The movable base 45 is configured to bemovable in the horizontal direction along the guide member 28 while notinterfering with the developing solution nozzle 23, for example, bymeans of a drive source (not illustrated) forming a movement mechanismtogether with the elevating/lowering mechanism. A nozzle standby portion46 is a standby portion for the cleaning liquid nozzle 5.

The monitoring mechanism 6 includes a high-precision camera. Themonitoring mechanism 6 monitors the interface of a dry regionconstituting the boundary between a liquid layer and the dry region. Themonitoring mechanism 6 outputs the results of monitoring to a controller7.

The controller 7 is a computer that can execute a program. Thecontroller 7 includes a program for executing each step of the operationto be performed by the substrate processing apparatus 1. The controller7 is configured to output a control signal for controlling a movementmechanism for moving the developing solution supply system 25 and thedeveloping solution nozzle 23, a movement mechanism for moving the gassupply system 43, the gas nozzle 4, and the cleaning liquid nozzle 5,the drive mechanism 22 for driving the spin chuck 2, theelevating/lowering portion 33 for the inner cup 32, or the like based onthe program. The program is stored in a storage medium, such as a harddisk, a compact disc, a flash memory, a flexible disk, or a memory card,and is used by being installed on the computer from the storage medium.

Next, a series of methods for performing a developing process on thesubstrate S and then cleaning the substrate S using the substrateprocessing apparatus 1 will be described. First, the outer cup 31 andthe inner cup 32 are located at the lowered positions, and thedeveloping solution nozzle 23, the gas nozzle 4, and the cleaning liquidnozzle 5 wait at predetermined standby positions. In such a standbystate, the substrate S is transferred by the substrate transfer means(not illustrated). The transferred substrate S has a surface coated withresist and further has been subjected to drawing. The substrate S isdelivered to the spin chuck 2 with the cooperative action of thesubstrate transfer means and the elevating/lowering pins (notillustrated). In this example, a highly water-repellent material is usedas the resist. Therefore, the static contact angle of the surface of thesubstrate S with respect to water is 90 degrees, for example.

The outer cup 31 and the inner cup 32 are set at the elevated positions.A developing solution is supplied onto the substrate S from thedeveloping solution nozzle 23. Herein, the developing solution issupplied using a known method. In this example, the discharge port 23 aof the developing solution nozzle 23 is set at a position severalmillimeters higher than the surface of the substrate S, for example.After that, the substrate S is rotated at a rotational speed of 1000 to1200 rpm, for example. In the state where the substrate S is rotated,the developing solution nozzle 23 is moved in the direction of theradius of rotation of the substrate S, that is, from the outer side tothe center side of the substrate S while a developing solution isdischarged from the discharge port 23 a in a belt-like manner. Thedeveloping solution nozzle 23 may also be moved from the center side tothe outer side of the substrate S, or oscillated.

The developing solution discharged in a belt-like manner from thedischarge port 23 a is continuously supplied to a region from the outerside to the inner side of the substrate S. Accordingly, the developingsolution is supplied to the entire surface of the substrate S in aspiral manner. With a centrifugal force acting on the rotating substrateS, the developing solution expands outward along the surface of thesubstrate S, and consequently, a thin liquid film is formed on thesurface of the substrate S. Then, a soluble portion of the resistdissolves in the developing solution, while an insoluble portion of theresist to form a pattern thereafter remains.

Next, replacing the developing solution nozzle 23, the cleaning liquidnozzle 5 is arranged above the central portion of the substrate S.Immediately after the developing solution nozzle 23 has stopped thesupply of the developing solution, a cleaning liquid is promptlydischarged from the cleaning liquid nozzle 5 to clean the surface of thesubstrate S. After the developing solution is washed away with thecleaning liquid, the surface of the substrate S should be dried.

As a method for drying the surface of the substrate S, a spin dryingmethod is known that rotates the substrate S to remove the cleaningliquid with a centrifugal force. However, due to the development step,the surface of the substrate S has both a portion where a resist patternis formed and a portion where a resist pattern is not formed. Theportion where the resist pattern is formed and the portion where theresist pattern is not formed differ in the degree of hydrophilicity ofthe surface with respect to the cleaning liquid.

Therefore, when the spin drying method is used, the drying time woulddiffer between the portions with different degrees of hydrophilicity.Thus, the boundary between the liquid film of the cleaning liquid andthe dry region where the liquid film has been removed would bedisturbed, with the result that the liquid film may fall apart intodroplets and the droplets remain on the substrate S. If the residualdroplets are minute droplets, such droplets are difficult to be shakenoff with a centrifugal force, and thus will remain on the substrate S.The residual droplets in turn form a reaction product, such as awatermark, causing defects.

To suppress the generation of such defects resulting from the residue ofminute droplets, a combination drying method may be used that combinesthe supply of a cleaning liquid and the injection of a dry gas. Thecombination drying method includes:

(1) supplying a cleaning liquid to the center of a substrate beingrotated to spread the cleaning liquid over the entire surface of thesubstrate,

(2) while the substrate is rotated, moving the landing position of thecleaning liquid on the substrate surface from the center side to theperipheral edge side of the substrate by a predetermined distance andalso discharging a dry gas to the center of the substrate to form a dryregion in the central portion of the substrate, and

(3) while the substrate is rotated, forming an interface of the dryregion by maintaining a state in which the landing position of thecleaning liquid and the landing position of the dry gas on the substratesurface are separated from each other by a constant distance, andfurther moving the interface of the dry region to the peripheral edgeside of the substrate to expand the dry region.

It should be noted that the “interface of the dry region” refers to theaforementioned boundary between the liquid film and the dry region.

In the combination drying method, along with the movement of the landingposition of the cleaning liquid and the landing position of the dry gasto the peripheral edge side of the substrate, the interface of the dryregion also moves to the peripheral edge side of the substrate. Thus,the dry region formed in the central portion of the substrate alsoexpands outward. As the interface of the dry region is actively formedand moved, the disturbance of the interface of the dry region can besuppressed, and thus, a residue of minute droplets can be prevented,which would otherwise be generated due to the falling apart of theliquid film. Consequently, it is expected that the generation of defectsresulting from a residue of minute droplets is suppressed.

A substrate, which has a resist pattern formed thereon through resistapplication, drawing, and a development process, was cleaned and driedwith the combination drying method, and was then inspected and observedfor the presence of detects. FIG. 3 illustrates the positions of thegenerated defects confirmed through the inspection and observation forthe presence of detects. The defects have been generated in a region onthe inner side of a circle with a radius of about 13 mm from the centerof the substrate.

The size and shape of a dry region initially formed in the center of thesubstrate with the combination drying method is a circle with a radiusof about 13 mm. That is, a region for forming a dry region is a circlewith a radius of about 13 mm. The time from when a dry region starts tobe generated with a dry gas blown thereto to when the dry region becomesa circle with a radius of about 13 mm is about 0.2 sec. After the dryregion has become a circle with a radius of about 13 mm, the interfaceof the dry region is moved to the peripheral edge side of the substratewhile a state in which the landing position of the cleaning liquid andthe landing position of the dry gas are separated from each other by aconstant distance is maintained, so that the dry region is expanded.That is, a region for expanding the dry region is a circle with a radiusof greater than or equal to 13 mm.

FIG. 4 illustrates the results obtained by taking a video of theexpanding dry region and calculating the movement speed of the interfaceof the dry region through analysis of the video. The movement speed ofthe interface is over 50 mm/sec on the inner side of the circle with aradius of 13 mm from the center of the substrate, that is, in the regionfor forming the dry region. The movement speed of the interface is 7mm/sec on the outer side of the circle with a radius of 13 mm from thecenter of the substrate, that is, in the region for expanding the dryregion.

The movement speed of the interface of the dry region is much faster inthe region for initially forming the dry region than in the region forexpanding the dry region. As illustrated in FIG. 5 , there is a highrisk that droplets may remain at the position where the degree ofhydrophilicity greatly changes, and such a risk is considered to furtherincrease if the interface of the dry region passes through the positionat a speed greater than or equal to a given speed.

Thus, the present embodiment provides a method for suppressing thegeneration of defects resulting from a residue of minute droplets bysuppressing the movement speed of the interface of the dry region. Thenozzle holding portion 41 of the present embodiment will be describedwith reference to FIG. 6 . The nozzle holding portion 41 holds the gasnozzle 4 and the cleaning liquid nozzle 5.

The cleaning liquid nozzle 5 is configured to be moved by an actuator52. The actuator 52 controls the cleaning liquid nozzle 5 to change thecleaning liquid injection direction in response to a control signaloutput from the controller 7. Next, a substrate processing method of thepresent embodiment will be described with reference to FIG. 7 . Thesubstrate processing method according to the present embodiment includesa liquid layer forming step, a dry region forming step, and a dry regionexpanding step.

Hereinafter, the details of the substrate processing method according tothe present embodiment will be described.

Step 1 (i.e., a liquid layer forming step): A substrate S, which has aresist pattern formed thereon through resist application, drawing, and adevelopment process, is prepared. The substrate S is rotated and acleaning liquid is supplied thereto from the cleaning liquid nozzle 5 toform a liquid layer W (see FIG. 7A). More specifically, the nozzleholding portion 41 is moved to allow the cleaning liquid nozzle 5 to bearranged opposite the central portion of the substrate S. The positionof the tip end of the cleaning liquid nozzle 5 is set at a level of 15mm, for example, from the surface of the substrate S. The spin chuck 2is rotated with a number of revolutions of 1000 rpm, for example. Purewater, for example, is discharged as the cleaning liquid to the centralportion of the substrate S from the cleaning liquid nozzle 5 at a flowrate of 250 ml/minute for 5 seconds. Accordingly, the cleaning liquidexpands from the central portion to the peripheral edge of the substrateS with a centrifugal force so that the developing solution is washedaway with the cleaning liquid. It should be noted that the centralportion of the substrate S means the center point of the substrate S andits vicinity.

Step 2 (i.e., a dry region forming step): As illustrated in FIG. 7B, thenozzle holding portion 41 is moved to allow the gas nozzle 4 to bearranged opposite the central portion of the substrate S. The cleaningliquid nozzle 5 is moved so that a cleaning liquid injected therefrom isdirected to the outer side of the central portion of the substrate S andon the outer side of a gas injected from the gas nozzle 4. That is, thetip end of the cleaning liquid nozzle 5 is inclined at an angle ofgreater than 0 degree and less than 90 degrees with respect to adirection perpendicular to the substrate, for example. In the state ofFIG. 7B, a gas is injected from the gas nozzle 4, and a cleaning liquidis injected from the cleaning liquid nozzle 5. Next, as illustrated inFIG. 7C, the cleaning liquid nozzle 5 is moved to allow the cleaningliquid injection direction of the cleaning liquid nozzle 5 to be awayfrom the gas injection direction of the gas nozzle 4. The oscillationspeed is adjusted to allow the movement speed of the interface L of thedry region to be 7 mm/sec. The movement speed of the interface L of thedry region may also be adjusted by feeding back the monitoring resultsof the monitoring mechanism 6, for example. The movement speed of theinterface L of the dry region is desirably less than 50 mm/sec, or moredesirably less than 20 mm/sec. As illustrated in FIG. 7D, the cleaningliquid injection direction of the cleaning liquid nozzle 5 is graduallymoved outward so as to adjust the dry region to become a circle with aradius of about 13 mm.

Step 3 (i.e., a dry region expanding step): As illustrated in FIG. 7E, astate in which the gas landing position of the gas injected from the gasnozzle 4 on the substrate S and the cleaning liquid landing position ofthe cleaning liquid injected from the cleaning liquid nozzle 5 on thesubstrate S are separated from each other by a distance of about 15 mmis maintained, and the nozzle holding portion 41 is moved to theperipheral edge side of the substrate so as to expand the dry region.After the entire surface of the substrate S was dried, the surface wasinspected and observed for the presence of detects. Then, it wasconfirmed that defects resulting from a residue of droplets werereduced.

First Modified Example

A nozzle holding portion 41A as a first modified example of the presentembodiment will be described with reference to FIG. 8 . The nozzleholding portion 41A holds a gas nozzle 4 and a cleaning liquid nozzle 5.

The cleaning liquid nozzle 5 is configured to be moved along the surfaceof the substrate S by an actuator 52A. The actuator 52A controls thecleaning liquid nozzle 5 to change the position of the cleaning liquidnozzle 5 in response to a control signal output from the controller 7.Next, a substrate processing method that uses the nozzle holding portion41A as the first modified example will be described with reference toFIG. 9 . The substrate processing method that uses the nozzle holdingportion 41A according to the first modified example also includes aliquid layer forming step, a dry region forming step, and a dry regionexpanding step.

Hereinafter, the details of the substrate processing method according tothe first modified example of the present embodiment will be described.

Step 1 (i.e., a liquid layer forming step): A substrate S, which has aresist pattern formed thereon through resist application, drawing, and adevelopment process, is prepared. The substrate S is rotated and acleaning liquid is supplied thereto from the cleaning liquid nozzle 5 toform a liquid layer (see FIG. 9A). More specifically, the nozzle holdingportion 41A is moved to allow the cleaning liquid nozzle 5 to bearranged opposite the central portion of the substrate S. The positionof the cleaning liquid nozzle 5 is set at a level of 15 mm, for example,from the surface of the substrate S. The spin chuck 2 is rotated with anumber of revolutions of 1000 rpm, for example. Pure water, for example,is discharged as the cleaning liquid to the central portion of thesubstrate S from the cleaning liquid nozzle 5 at a flow rate of 250ml/minute for 5 seconds. Accordingly, the cleaning liquid expands fromthe central portion to the peripheral edge of the substrate S with acentrifugal force so that the developing solution is washed away withthe cleaning liquid. It should be noted that the central portion of thesubstrate S means the center point of the substrate S and its vicinity.

Step 2 (i.e., a dry region forming step): As illustrated in FIG. 9B, thenozzle holding portion 41A is moved to allow the gas nozzle 4 to bearranged opposite the central portion of the substrate S. The cleaningliquid nozzle 5 is arranged to allow a cleaning liquid injectedtherefrom to be arranged on the outer side of the central portion of thesubstrate S and on the outer side of a gas injected from the gas nozzle4. In the state of FIG. 9B, a gas is injected from the gas nozzle 4, anda cleaning liquid is injected from the cleaning liquid nozzle 5. Next,as illustrated in FIG. 9C, the cleaning liquid nozzle 5 is moved in thehorizontal direction with respect to the substrate S so as to allow thecleaning liquid injection position of the cleaning liquid nozzle 5 to beaway from the gas injection position of the gas nozzle 4. The movementspeed is adjusted to allow the movement speed of the interface L of thedry region to be 7 mm/sec. As illustrated in FIG. 9D, the cleaningliquid injection position of the cleaning liquid nozzle 5 is graduallymoved outward in the horizontal state with respect to the substrate S soas to adjust the dry region to become a circle with a radius of about 13mm.

Step 3 (i.e., a dry region expanding step): As illustrated in FIG. 9E, astate in which the gas landing position of the gas injected from the gasnozzle 4 on the substrate S and the cleaning liquid landing position ofthe cleaning liquid injected from the cleaning liquid nozzle 5 on thesubstrate S are separated from each other by a distance of about 15 mmis maintained, and the nozzle holding portion 41A is moved to theperipheral edge side of the substrate so as to expand the dry region.After the entire surface of the substrate S was dried, the surface wasinspected and observed for the presence of detects. Then, it wasconfirmed that defects resulting from a residue of droplets werereduced.

Second Modified Example

A nozzle holding portion 41B as a second modified example of the presentembodiment will be described with reference to FIG. 10 . The nozzleholding portion 41B holds a gas nozzle 4 and cleaning liquid nozzles5Ba, 5Bb, 5Bc, 5Bd, 5Be, and 5Bf. In the second modified example, asingle gas nozzle 4 and six cleaning liquid nozzles 5Ba, 5Bb, 5Bc, 5Bd,5Be, and 5Bf are arranged in a row.

The cleaning liquid nozzle 5Ba is configured such that its injection andstop of a cleaning liquid are adjusted by opening and closing a valve52Ba. The cleaning liquid nozzle 5Bb is configured such that itsinjection and stop of a cleaning liquid are adjusted by opening andclosing a valve 52Bb. The cleaning liquid nozzle 5Bc is configured suchthat its injection and stop of a cleaning liquid are adjusted by openingand closing a valve 52Bc. The cleaning liquid nozzle 5Bd is configuredsuch that its injection and stop of a cleaning liquid are adjusted byopening and closing a valve 52Bd. The cleaning liquid nozzle 5Be isconfigured such that its injection and stop of a cleaning liquid areadjusted by opening and closing a valve 52Be. The cleaning liquid nozzle5Bf is configured such that its injection and stop of a cleaning liquidare adjusted by opening and closing a valve 52Bf. Each of the valves52Ba, 52Bb, 52Bc, 52Bd, 52Be, and 52Bf for the cleaning liquid nozzlesis opened or closed in response to a control signal output from thecontroller 7 so as to adjust the injection of a cleaning liquid from thecorresponding cleaning liquid nozzle. Next, a substrate processingmethod that uses the nozzle holding portion 41B as the second modifiedexample will be described with reference to FIG. 11 . The substrateprocessing method that uses the nozzle holding portion 41B according tothe second modified example also includes a liquid layer forming step, adry region forming step, and a dry region expanding step.

Hereinafter, the details of the substrate processing method according tothe second modified example of the present embodiment will be described.

Step 1 (i.e., a liquid layer forming step): A substrate S, which has aresist pattern formed thereon through resist application, drawing, and adevelopment process, is prepared. The substrate S is rotated and acleaning liquid is supplied thereto from each of the cleaning liquidnozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be, and 5Bf to form a liquid layer W (seeFIG. 11A). More specifically, the nozzle holding portion 41B is moved toallow the cleaning liquid nozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be, and 5Bf to bearranged opposite the central portion of the substrate S. The positionsof the tip ends of the cleaning liquid nozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be,5Bf are set at a level of 15 mm, for example, from the surface of thesubstrate S. The spin chuck 2 is rotated with a number of revolutions of1000 rpm, for example. Pure water, for example, is discharged as thecleaning liquid to the central portion of the substrate S from each ofthe cleaning liquid nozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be, and 5Bf at a flowrate of 250 ml/minute, for example, for 5 seconds, for example.Accordingly, the cleaning liquid expands from the central portion to theperipheral edge of the substrate S with a centrifugal force so that thedeveloping solution is washed away with the cleaning liquid. It shouldbe noted that the central portion of the substrate S means the centerpoint of the substrate S and its vicinity.

Step 2 (i.e., a dry region forming step): As illustrated in FIG. 11B,the nozzle holding portion 41B is moved to allow the gas nozzle 4 to bearranged opposite the central portion of the substrate S. Each of thecleaning liquid nozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be, and 5Bf is arranged toallow a cleaning liquid injected therefrom to be arranged on the outerside of the central portion of the substrate S and on the outer side ofa gas injected from the gas nozzle 4. In the state of FIG. 11B, a gas isinjected from the gas nozzle 4, and a cleaning liquid is injected fromeach of the cleaning liquid nozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be, and 5Bf.Next, as illustrated in FIG. 11C, the injection of the cleaning liquidfrom the cleaning liquid nozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be, and 5Bf issequentially stopped so as to allow the cleaning liquid injectionpositions of the cleaning liquid nozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be, and5Bf to be away from the gas injection position of the gas nozzle 4. Morespecifically, the injection of the cleaning liquid from the cleaningliquid nozzle 5Ba is stopped first, and next, the injection of thecleaning liquid from the cleaning liquid nozzle 5Bb is stopped, theinjection of the cleaning liquid from the cleaning liquid nozzle 5Bc isstopped, and the injection of the cleaning liquid from the cleaningliquid nozzle 5Bd is stopped. The speed of sequentially stopping theinjection of the cleaning liquid is adjusted to allow the movement speedof the interface L of the dry region to be 7 mm/sec. As illustrated inFIG. 11D, the cleaning liquid injection positions of the cleaning liquidnozzles 5Ba, 5Bb, 5Bc, 5Bd, 5Be, and 5Bf are gradually moved outward soas to adjust the dry region to become a circle with a radius of about 13mm.

Step 3 (i.e., a dry region expanding step): As illustrated in FIG. 11E,a state in which the gas landing position of the gas injected from thegas nozzle 4 on the substrate S and the cleaning liquid landing positionof the cleaning liquid injected from each of the cleaning liquid nozzles5Be and 5Bf on the substrate S are separated from each other by adistance of about 15 mm is maintained, and the nozzle holding portion41B is moved to the peripheral edge side of the substrate so as toexpand the dry region. After the entire surface of the substrate S wasdried, the surface was inspected and observed for the presence ofdetects. Then, it was confirmed that defects resulting from a residue ofdroplets were reduced.

Third Modified Example

A nozzle holding portion 41C as a third modified example of the presentembodiment will be described with reference to FIG. 12 . The nozzleholding portion 41C includes a gas nozzle 4 and a cleaning liquid nozzle5C.

The cleaning liquid nozzle 5C is configured such that a oscillationstate of the cleaning liquid nozzle 5C and/or the injection angle of acleaning liquid injected from the tip end thereof is adjustable. Thecleaning liquid nozzle 5C includes an injection angle adjustment member52C. As the injection angle adjustment member 52C moves up and down, theangle of a cleaning liquid injected from the cleaning liquid nozzle 5Cis adjusted. The injection angle adjustment member 52C controls thecleaning liquid nozzle 5C to change the angle of a cleaning liquidinjected from the cleaning liquid nozzle 5C in response to a controlsignal output from the controller 7. Next, a substrate processing methodthat uses the nozzle holding portion 41C as the third modified examplewill be described with reference to FIG. 13 . The substrate processingmethod that uses the nozzle holding portion 41A according to the thirdmodified example also includes a liquid layer forming step, a dry regionforming step, and a dry region expanding step.

Hereinafter, the details of the substrate processing method according tothe third modified example of the present embodiment will be described.

Step 1 (i.e., a liquid layer forming step): A substrate S, which has aresist pattern formed thereon through resist application, drawing, and adevelopment process, is prepared. The substrate S is rotated and acleaning liquid is supplied thereto from the cleaning liquid nozzle 5Cto form a liquid layer W (see FIG. 13A). More specifically, the nozzleholding portion 41C is moved to allow the cleaning liquid nozzle 5C tobe arranged opposite the central portion of the substrate S. Theposition of the cleaning liquid nozzle 5C is set at a level of 15 mm,for example, from the surface of the substrate S. The spin chuck 2 isrotated with a number of revolutions of 1000 rpm, for example. Purewater, for example, is discharged as the cleaning liquid to the centralportion of the substrate S from the cleaning liquid nozzle 5C at a flowrate of 250 ml/minute, for example, for 5 seconds, for example.Accordingly, the cleaning liquid expands from the central portion to theperipheral edge of the substrate S with a centrifugal force so that thedeveloping solution is washed away with the cleaning liquid. It shouldbe noted that the central portion of the substrate S means the centerpoint of the substrate S and its vicinity.

Step 2 (i.e., a dry region forming step): As illustrated in FIG. 13B,the nozzle holding portion 41C is moved to allow the gas nozzle 4 to bearranged opposite the central portion of the substrate S. The angle of acleaning liquid injected from the cleaning liquid nozzle 5C is adjustedto a wide angle so that the injected cleaning liquid is arranged on theouter side of the central portion of the substrate S and on the outerside of a gas injected from the gas nozzle 4. In the state of FIG. 13B,a gas is injected from the gas nozzle 4, and a cleaning liquid isinjected from the cleaning liquid nozzle 5C. Next, as illustrated inFIG. 13C, the angle of the cleaning liquid injected from the cleaningliquid nozzle 5C is gradually made narrower so as to allow the cleaningliquid injection position of the cleaning liquid nozzle 5C to be awayfrom the gas injection position of the gas nozzle 4. The speed ofnarrowing the cleaning liquid injection angle is adjusted to allow themovement speed of the interface L of the dry region to be 7 mm/sec. Asillustrated in FIG. 13D, the cleaning liquid injection position of thecleaning liquid nozzle 5C is gradually moved outward so as to adjust thedry region to become a circle with a radius of about 13 mm.

Step 3 (i.e., a dry region expanding step): As illustrated in FIG. 13E,a state in which the gas landing position of the gas injected from thegas nozzle 4 on the substrate S and the cleaning liquid landing positionof the cleaning liquid injected from the cleaning liquid nozzle 5C onthe substrate S are separated from each other by a distance of about 15mm is maintained, and the nozzle holding portion 41C is moved to theperipheral edge side of the substrate so as to expand the dry region.After the entire surface of the substrate S was dried, the surface wasinspected and observed for the presence of detects. Then, it wasconfirmed that defects resulting from a residue of droplets werereduced.

In each step 2 described with reference to FIGS. 6 to 13 , the movementspeed of the interface L of the dry region is set to 7 mm/sec, but themovement speed is not limited thereto. The movement speed of theinterface L of the dry region can be changed to be within a given rangeas long as no defects would ultimately be generated due to a residue ofdroplets. In each step 3 described with reference to FIGS. 6 to 13 , thedry region is expanded in the state where the gas landing position andthe cleaning liquid landing position are separated from each other by adistance of about 15 mm, but the separation distance can be changed asappropriate. In step 3, the injection of the gas may also be stopped.

As described above, the present embodiment provides the substrateprocessing apparatus 1 for cleaning and drying the substrate S as thesubstrate under processing, the substrate processing apparatus 1including the cleaning liquid nozzle 5 that supplies a cleaning liquidonto the substrate under processing, the gas nozzle 4 that supplies agas onto the substrate under processing, and the controller 7 thatcontrols the state of supply of the cleaning liquid from the cleaningliquid nozzle 5 and the state of supply of the gas from the gas nozzle4. The controller 7 causes the cleaning liquid nozzle 5 to supply acleaning liquid onto the substrate under processing to form a cleaningliquid layer, and causes the gas nozzle 4 to supply a gas onto thesubstrate under processing to partially remove the cleaning liquid layerand thus form a first dry region on the substrate under processing (seeFIGS. 7B, 9B, 11B, and 13B), and then expands the first dry region toform a second dry region by controlling the movement speed of theboundary between the cleaning liquid layer and the first dry region tobe less than or equal to a predetermined speed (see FIGS. 7C and 7D, 9C,9D, 11C, 11D, 13C, and 13D), and further expands the second dry regionto form a third dry region (see FIGS. 7E, 9E, 11E, and 13E). The firstdry region may be an extremely small region, for example, a region witha diameter of about 1 nm. It is also possible to expand the first dryregion to generate the second dry region by controlling the movementspeed of the boundary between the cleaning liquid layer and the firstdry region to be less than or equal to a predetermined speed immediatelyafter supplying a gas onto the substrate under processing from the gasnozzle 4.

As described above, the present embodiment provides a substrateprocessing method for cleaning and drying the substrate S as thesubstrate under processing, the method including supplying a cleaningliquid onto the substrate under processing to form a cleaning liquidlayer, supplying a gas onto the substrate under processing to partiallyremove the cleaning liquid layer and thus generate a first dry region onthe substrate under processing (see FIGS. 7B, 9B, 11B, and 13B),expanding the first dry region to generate a second dry region bycontrolling the movement speed of the boundary between the cleaningliquid layer and the first dry region to be less than or equal to apredetermined speed, (see FIGS. 7C, 7D, 9C, 9D, 11C, 11D, 13C, and 13D),and further expanding the second dry region to generate a third dryregion (see FIGS. 7E, 9E, 11E, and 13E). The first dry region may be anextremely small region, for example, a region with a diameter of about 1nm. It is also possible to expand the first dry region to generate thesecond dry region by controlling the movement speed of the boundarybetween the cleaning liquid layer and the first dry region to be lessthan or equal to a predetermined speed immediately after supplying a gasonto the substrate under processing from the gas nozzle 4.

Each of the first dry region, the second dry region, and the third dryregion is formed by adjusting at least one of the liquid landingposition of the cleaning liquid on the substrate under processing andthe gas landing position of the gas on the substrate under processing.

Second Embodiment

Another substrate processing method that uses the nozzle holding portion41 according to the present embodiment will be described with referenceto FIG. 14 . The substrate processing method according to the presentembodiment includes a liquid layer forming step, a dry region formingstep, and a dry region expanding step. It should be noted that theconfiguration of the substrate processing apparatus 1 according to thepresent embodiment is similar to that of the first embodiment.

Hereinafter, the details of the substrate processing method according tothe present embodiment will be described.

Step 1 (i.e., a liquid layer forming step): A substrate S, which has aresist pattern formed thereon through resist application, drawing, and adevelopment process, is prepared. The substrate S is rotated, and acleaning liquid is supplied thereto from the cleaning liquid nozzle 5 toform a liquid layer W (see FIG. 14A). More specifically, the nozzleholding portion 41 is moved to allow the cleaning liquid nozzle 5 to bearranged opposite the central portion of the substrate S. The positionof the cleaning liquid nozzle 5 is set at a level of 15 mm, for example,from the surface of the substrate S. The spin chuck 2 is rotated with anumber of revolutions of 1000 rpm, for example. Pure water, for example,is discharged as the cleaning liquid to the central portion of thesubstrate S from the cleaning liquid nozzle 5 at a flow rate of 250ml/minute, for example, for 5 seconds, for example. Accordingly, thecleaning liquid expands from the central portion to the peripheral edgeof the substrate S with a centrifugal force so that the developingsolution is washed away with the cleaning liquid. It should be notedthat the central portion of the substrate S means the center point ofthe substrate S and its vicinity.

Step 2 (i.e., a dry region forming step): As illustrated in FIG. 14B,the nozzle holding portion 41 is moved to allow the gas nozzle 4 to bearranged opposite the central portion of the substrate S. In the stateof FIG. 14B, a gas is injected from the gas nozzle 4, and a cleaningliquid is injected from the cleaning liquid nozzle 5. The gas isinjected to the center of the substrate S, and the cleaning liquid isinjected to a position away from the center of the substrate S by about15 mm so that a circular dry region with a radius of about 13 mm isformed on the central portion of the substrate S. Next, as illustratedin FIG. 14C, the landing position of the cleaning liquid is moved to thecenter side of the substrate S by 10 mm so as to adjust the circular dryregion to have a radius of about 3 mm.

Step 3 (i.e., a dry region expanding step): As illustrated in FIG. 14D,a state in which the gas landing position of the gas injected from thegas nozzle 4 on the substrate S and the cleaning liquid landing positionof the cleaning liquid injected from the cleaning liquid nozzle 5 on thesubstrate S are separated from each other by a distance of about 15 mmis maintained, and the nozzle holding portion 41 is moved to theperipheral edge side of the substrate so as to expand the dry region.After the entire surface of the substrate S was dried, the surface wasinspected and observed for the presence of detects. Then, it wasconfirmed that defects resulting from a residue of droplets werereduced.

In step 2 described with reference to FIG. 14B, the dry region isexpanded in the state where the gas landing position and the cleaningliquid landing position are separated from each other by a distance ofabout 15 mm, but the separation distance can be changed as appropriate.The radius of the dry region formed in the central portion of thesubstrate S is not limited to about 13 mm. After the dry region isformed, the injection of the gas may also be stopped. In step 2, themovement distance of the cleaning liquid landing position to the centerside of the substrate S is not limited to about 10 mm. The radius of theadjusted dry region is not limited to about 3 mm. In step 3, the dryregion is expanded in the state where the gas landing position and thecleaning liquid landing position are separated from each other by adistance of about 15 mm, but the separation distance can be changed asappropriate.

As described above, the present embodiment provides the substrateprocessing apparatus 1 for cleaning and drying the substrate underprocessing, the substrate processing apparatus 1 including the cleaningliquid nozzle 5 that supplies a cleaning liquid onto the substrate underprocessing, the gas nozzle 4 that supplies a gas onto the substrateunder processing, and the controller 7 that controls the state of supplyof the cleaning liquid from the cleaning liquid nozzle 5 and the stateof supply of the gas from the gas nozzle 4. The controller 7 causes thecleaning liquid nozzle 5 to supply a cleaning liquid onto the substrateunder processing to form a cleaning liquid layer, and causes the gasnozzle 4 to supply a gas onto the substrate under processing topartially remove the cleaning liquid layer and thus generate a first dryregion on the substrate under processing (see FIG. 14B), and thenreduces the first dry region to generate a fourth dry region (see FIG.14C), and further expands the fourth dry region to generate a fifth dryregion (see FIG. 14D).

As described above, the present embodiment provides a substrateprocessing method for cleaning and drying the substrate S as thesubstrate under processing, the method including supplying a cleaningliquid onto the substrate under processing to from a cleaning liquidlayer, and supplying a gas onto the substrate under processing topartially remove the cleaning liquid layer and thus generate a first dryregion on the substrate under processing (see FIG. 14(B)), and thenreducing the first dry region to generate a fourth dry region (see FIG.14(C)), and further expanding the fourth dry region to generate a fifthdry region (see FIG. 14(D)).

It is also possible to reduce the first dry region to generate thefourth dry region and further expand the fourth dry region to generatethe fifth dry region by controlling the movement speed of the boundarybetween the cleaning liquid layer and the first dry region to be lessthan or equal to a predetermined speed.

Each of the first dry region, the fourth dry region, and the fifth dryregion is formed by adjusting at least one of the liquid landingposition of the cleaning liquid on the substrate under processing andthe gas landing position of the gas on the substrate under processing.

In the description of the embodiments and the modified examples, theliquid landing position may also be adjusted based on the flow rate ofthe discharged cleaning liquid, for example. The gas landing positionmay also be adjusted based on the flow rate of the discharged gas, forexample.

Although the embodiments have been described with reference to specificexamples, the present disclosure is not limited thereto. Such specificexamples are, even when some design changes are made thereto asappropriate by one of ordinary skill in the art, also included in thescope of the present disclosure as long as the resulting design includesthe features of the present disclosure. The components, theirarrangement, conditions, shapes, and the like of each of theaforementioned specific examples are not limited to those exemplarilyillustrated above, and can be changed as appropriate. A combination ofthe components of each of the aforementioned specific examples can bechanged as appropriate unless any technical contradiction occurs.

What is claimed is:
 1. A substrate processing apparatus for cleaning anddrying a substrate under processing, comprising: a liquid nozzle thatsupplies a liquid onto the substrate under processing to form a liquidlayer; a gas nozzle that supplies a gas onto the substrate underprocessing to form a dry region; a controller configured to control theliquid nozzle and the gas nozzle; and a monitoring mechanism configuredto monitor an interface of the dry region constituting a boundarybetween the liquid layer and the dry region, wherein: the controller isconfigured to, based on a monitoring result of the monitoring mechanism,form the dry region by controlling a movement speed of the interface ofthe dry region to be less than or equal to a predetermined speed whilecausing the liquid nozzle to supply the liquid and causing the gasnozzle to supply the gas.
 2. A substrate processing apparatus forcleaning and drying a substrate under processing, comprising: a liquidnozzle that supplies a liquid onto the substrate under processing toform a liquid layer; a gas nozzle that supplies a gas onto the substrateunder processing to form a dry region; a controller configured tocontrol the liquid nozzle and the gas nozzle; and a monitoring mechanismconfigured to monitor an interface of the dry region constituting aboundary between the liquid layer and the dry region, wherein: thecontroller is configured to, based on a monitoring result of themonitoring mechanism, cause the liquid nozzle to supply a cleaningliquid onto the substrate under processing, thereby forming a cleaningliquid layer, and cause the gas nozzle to supply the gas while causingthe liquid nozzle to supply the liquid, thereby generating the dryregion on the substrate under processing, and then reduce the dryregion, and further expand the dry region.
 3. The substrate processingapparatus according to claim 1, wherein the controller is configured to,to form the dry region, adjust at least one of a liquid landing positionof the liquid on the substrate under processing and a gas landingposition of the gas on the substrate under processing.
 4. The substrateprocessing apparatus according to claim 2, wherein the controller isconfigured to, to form the dry region, adjust at least one of a liquidlanding position of the liquid on the substrate under processing and agas landing position of the gas on the substrate under processing. 5.The substrate processing apparatus according to claim 1, wherein thecontroller is configured to, based on the monitoring result of themonitoring mechanism, control an oscillation state or an injection angleof the liquid nozzle.
 6. The substrate processing apparatus according toclaim 1, wherein the controller is configured to, based on themonitoring result of the monitoring mechanism, control an oscillationstate or an injection angle of the liquid nozzle.
 7. A substrateprocessing method for cleaning and drying a substrate under processing,comprising: supplying a liquid onto the substrate under processing toform a liquid layer; supplying a gas onto the substrate under processingto partially remove the liquid layer and thus generate a dry region onthe substrate under processing; and expanding the dry region bycontrolling a movement speed of an interface of the dry regionconstituting a boundary between the liquid layer and the dry region tobe less than or equal to a predetermined speed.
 8. A substrateprocessing method for cleaning and drying a substrate under processing,comprising: supplying a liquid onto the substrate under processing toform a liquid layer; supplying a gas onto the substrate under processingto partially remove the liquid layer and thus generate a dry region onthe substrate under processing; and reducing the dry region and thenexpanding the dry region.
 9. The substrate processing method accordingto claim 7, further comprising, to form the dry region, adjusting atleast one of a liquid landing position of the cleaning liquid on thesubstrate under processing and a gas landing position of the gas on thesubstrate under processing.
 10. The substrate processing methodaccording to claim 8, further comprising, to form the dry region,adjusting at least one of a liquid landing position of the cleaningliquid on the substrate under processing and a gas landing position ofthe gas on the substrate under processing.